1) 1 x 12v timer purchased from http://www.12volttimer.com/ £29.99 +p&p - (this is the most expensive part on the list)
2) 1 x Auto car aerial off ebay £14.99 (Although in a boot sale last weekend, I found one for £5)
3) 1m of 13amp power cord (old extension cable or something will do)
4) 5 x female spade connectors £0.50p (from local car shop)
5) 2 x curtain hooks (had them lying around shed - bent them to form 'eyes')
6)1.5m x (6"x1") - (this was in my timber pile)
7)1 x very small jubilee clip £0.25p (local DIY store)
8 )4 x 1/4" wood screws
9) 8 x 1/2" wood screws
10) length of garden twine (string, fishing line etc)
11) 1 x dog biscuit container (ice cream container, biscuit tin or some other container)
INSTRUCTIONS
Firstly I laid the lid of the biscuit container on the work surface and mounted the 12v timer with 4 x 1/4" screws in 1 corner of the lid.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00196.jpg)
Then positioned the aerial where it would fit inside the box allowing the lid to close correctly. This was fixed in place by the bracket that came with the aerial, a hole was pushed through the lid, and the bracket was bolted to the lid.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00197.jpg)
The next thing to do was to extend the aerial (connect positive and negative to car battery) When measured, this was 44", so I knew the container had to be mounted at least that height above the ground on the 1.5m plank.
Next the plank of wood was positioned at the side of the door, and secured with 4 x 1/2" wood screws through the body of the plastic coop.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00203.jpg)
The next thing was to fix the lid of the container at the correct height on the vertical plank of wood. This was done with 4 x 1/2" wood screws. I then secured a small piece of wood horizontal from the vertical plank at the point the door would open to.
1 of the hooks (eyes) was positioned in the horizontal piece of wood, above the centre of the door. The other was fixed as close to the aerial as possible, but higher than the first so the string would be pulled through both eyes and in line with the aerial as much as possible.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00202.jpg)
Next, I cut a hole at the right position in the 'body' of the box, for the aerial to extend through, and the cable to run through
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00204.jpg)
When the aerial was extended, I used the very small jubilee clip, and tied the one end of the string to it, and then clamped it to the end of the aerial.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00201.jpg)
I then fed it up through the one 'eye', down to the second, and then opened the door to the desired position, and tied the string to the hole in the door. When released, the door stayed in position.
![Image](http://i731.photobucket.com/albums/ww314/draygor/New%20birds/DSC00199.jpg)
The plastic box when shut forms a relatively water proof container. The little hole in the front of the container, is so that I can 'prod' the manual override button, should I wish to open or close the door manually.
WIRING IT ALL TOGETHER
The 12v timer has 5 terminal in it.
(Photo shows rear of timer)
![Image](http://i731.photobucket.com/albums/ww314/draygor/12-volt-timer.jpg)
![Image](http://i731.photobucket.com/albums/ww314/draygor/numbers.jpg)
Positions (1) & (2) are for 12v power input from the battery. When crimping a connector to the positive from the battery (1) , include another short piece of wire, and crimp. Crimp the other end of this wire to another spade connector and connect to terminal (5)
When crimping the negative wire from the battery, include the negative of the aerial and crimp. Connect this to terminal (2)
Terminal (3) has a separate length of single wire, and the positive from the aerial crimped together and connected. This single wire, must run back to the positive of the battery.
Terminal (4) has the 'switch' wire from the aerial connected to it. This is the wire that tells the aerial to switch direction when power is applied & removed
Next I connected the positive from the timer, and the single wire to the positive of the battery, and the negative from the timer to the negative of the battery. Pressing the manual button on the timer, allowed me to switch it to on and off, to test the aerial retracting and extending. (Watch for the string getting caught, and ensure that the door opens and closes fully.
For programming of the timer (which is very easy) visit http://www.12volttimer.com/ where there is a demo video.
I think I have covered everything, if my explanation is a little confusing, please pm me, and I will try to clarify.
PS. I am no electrician or DIY handyman, but I had a go, and was surprised at how relatively easy it was. I hit some snags, but plodded on and did it. I am chuffed to bits with the outcome, and the cost was far less than a commercially bought item. Apart from the timer, all other items can be sourced second hand making it even cheaper than mine.
Draygor